The present invention relates generally to a hermetic scroll-type compressor and, more particularly, to such a compressor having intermeshing fixed and orbiting scroll member assemblies, wherein each assembly comprises a separate involute wrap element connected to an end plate assembly.
A typical scroll compressor comprises two facing scroll members, each having an involute wrap, wherein the respective wraps interfit to define a plurality of closed pockets. When one of the scroll members is orbited relative to the other, the pockets travel between a radially outer suction port and a radially inner discharge port to convey and compress the refrigerant fluid.
It is generally believed that the scroll-type compressor could potentially offer quiet, efficient, and low maintenance operation in a variety of refrigeration system applications. However, several design and manufacturing problems persist that have prevented the scroll compressor from achieving wide market acceptance and commercial success. For instance, the fixed and orbiting scroll members are somewhat difficult and expensive to fabricate, thereby increasing the cost of a scroll-type compressor relative to other compressor types, e.g., reciprocating piston and rotary vane.
There are two basic constructional alternatives for fabricating scroll members, namely, forming them from a single piece of metal by machining out the involute wrap, or forming the involute wrap and end plate separately and then joining them into a finished scroll member. Fabricating an integrally formed scroll member requires excessive amounts of time and energy, and produces large quantities of waste metal. Also, computer-controlled milling machines used in mass production of these scroll members are quite expensive. Several methods of connecting a separately formed involute wrap to an end plate to form a scroll member have been proposed; however, none appears to have proven economically feasible for the purpose of mass producing scroll-type compressors.
The present invention is directed to overcoming the aforementioned problems associated with scroll-type compressors, wherein it is desired to provide an improved design for and method of manufacturing fixed and orbiting scroll members in order to reduce the manufacturing difficulty and costs associated therewith.